[Python-Dev] "and" and "or" operators in Py3.0

Nick Coghlan ncoghlan at gmail.com
Tue Sep 20 11:33:19 CEST 2005


Michael Hudson wrote:
> I _like_ the explanation of 'and' and 'or' as they are now.  They are
> basically control flow constructs -- and have to be to get
> short-circuiting to work -- and adding a coercion to bool at the end
> seems to add complexity, not reduce it (on some levels, anyway).

Agreed. However, Raymond and Brett seem to have some ideas about optimising 
the normal comparison bytecode without changing the semantics, which would be 
good.

>>P.S.  Simplifying "and" and "or" may create a need to introduce a
>>conditional operator but that is a discussion for another day.
> 
> 
> ... which was in the past, I thought.

C'mon, PEP 308 was fun for everybody };)

The ease of writing buggy code when trying to fake a conditional operator 
using and/or does seem to cause the question to keep coming up despite the 
fate of PEP 308, though. But the only way I can ever see a conditional 
operator happening is if Guido simply selects which of the top 4** PEP 308 
solutions he likes best and says "make it so!".

Cheers,
Nick.

** I say top 4, because there was daylight between the votes for the first 4 
choices and all of the other PEP 308 options. And many of the pros and cons of 
those 4 choices are so subjective that I wouldn't expect further discussion to 
significantly change anyone's opinion.

-- 
Nick Coghlan   |   ncoghlan at gmail.com   |   Brisbane, Australia
---------------------------------------------------------------
             http://boredomandlaziness.blogspot.com


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